Display screen or portion thereof with an animated graphical user interface



FIG. 1 is a front view of a first image of a display screen or portion thereof with an animated graphical user interface; and,

FIG. 2 is a front view of a second image thereof.

The broken lines showing the display screen or portion thereof form no part of the claimed design.

The appearance of the animated graphical user interface transitions sequentially between the images shown in FIGS. 1-2. The process or period in which one image transitions to another forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with an animated graphical user interface depicted in a sequence, as shown and described. 